There is no way... no way, that you could would buy Oh No! just from looking at the cover art. There's a cow with a space helmet on its head, an odd-looking furry animal, a desert and, in the background, a spacecraft.
The spacecraft is the important part. Oh No! is a shoot 'em up, and although the storyline is odd, the game most certainly is not...
In Oh No!, the year is 1,000,000 AD, and you are a breeder of space oxen. These beasts are very highly coveted by other entities, who will stop at nothing to get their hands or other genetically-modified appendages on them. The rustling bastards. So you must mount up on your trusty space-steed and put a stop to their stealing shenanigans.
The first planet is the easiest, but you'll still have to be cautious...
It's much simpler than it sounds as a game... confined within one screen, you must blast anything that comes within range and stop them from taking the oxen off the screen. If all the oxen are lost, the game is over. Them's the rules, and they're easy to follow...
And indeed, the game is simple in theory. Once you start playing it, though, you'll see that it's much more difficult in practice.
Oh No!, to my mind, stands right up there among the finest of frantic shooters. What it essentially does is to cross Robotron: 2084 with Defender and Missile Command. Wait... let me explain.
That pink thing looks familiar... if it wasn't nicked from Defender, I'll eat my hat.
You have a playfield where you have to protect your oxen... they're like The Last Human Family, but in bovine form. But unlike in Robotron, they're not killed when enemies get to them. Instead, they're captured, and you have a limited amount of time to rescue them before they're taken off the playfield. See, that's like Defender.
The game is split up into different planets, and each planet has nine waves, with each being progressively more manic than the last. There's no break between waves. Once you destroy every enemy in a wave, the next one rushes in without a second thought. If you want any kind of a break for your trigger finger, you'll have to wait nine waves for it.
Leave her alone, you BITCH!
As your only objective is to save your oxen, it's important to keep them close together or, if it all gets too much, let them all go except for one and be sure to defend that one to the end. That's the Missile Command aspect... it's very similar to your endgame there, where you concentrate on keeping one city intact.
Oh No! was well-reviewed by ZZAP! 64, but I'm not sure how well it sold or was received in general. Comments on Lemon64 seem to be mixed, but I absolutely loved this game when I bought it and I still play it occasionally now. It's a really pure shoot 'em up high-score experience, guaranteed to get the adrenalin pumping. Lovely stuff.